Even without signs of external injury, chemical exposure can produce severe trauma to internal target organs including the lungs, heart, gastrointestinal tract, eyes, and the central nervous system. Of these injuries, the extent of lung injury often is the most critical to survival. Chemical Induced Acute Lung Injury (CIALI) can be viewed as a molecular cascade mounting over hours and days subsequent to even a transient incident. Unfortunately, CIALI is a likely consequence of terrorist attacks of multiple possible scenarios including intentional detonation of chemical plants, railroad car derailment, or chemical truck hijacking. Chemicals of high concern include chlorine, phosgene, sulfuric acid, ammonia, and acrolein. Predictive strategies will require the monitoring of multiple biochemical indicators forming complex molecular signatures. Our goal is to understand the genetic, global transcriptomal, and molecular events that will provide insights into the mechanisms of CIALI and could redirect or strengthen current emergency clinical approaches to diagnosis and treatment. The objective of this application is to determine the molecular mechanism(s) and therapeutic efficacy of TGFalpha and FGF7 in enhancing survival in this condition. Our central hypothesis is that the interplay between TGFalpha, FGF7, and TGFbeta signaling determines survival and controls the susceptibility to sequelae from CIALI. To explore our hypothesis, we seek to: 1) Identify the genetic determinants and molecular mechanisms controlling CIALI common to exposure to 5 leading hazardous chemicals: chlorine, phosgene, sulfuric acid, ammonia, and acrolein, 2) Evaluate the therapeutic efficacy of TGFalpha and FGF7 induction and signaling during CIALI and determine whether pulmonary fibrosis is a necessary sequela as a consequence of protection, and 3) Identify the molecular mechanisms that are unique to each of the 5 leading hazardous chemicals during the early development of CIALI. At the completion of this project, we expect to: 1) Identify novel genetic differences that determine the susceptibility to CIALI, 2) Identify the events modulated during CIALI that are common to multiple agents 3) Evaluate the effectiveness of therapies by that lead to protection in CIALI, 4) Determine whether pulmonary fibrosis is an untoward consequence of activating TGFalpha/FGF7signaling during CIALI, 5) Develop an initial chemical specific database on the selective signatures of the 5 leading hazardous chemicals.